在本章中，我们将介绍基本的 CRUD操作.现在我们的系统已经准备好开始，因为我们已经成功实现了我们的域Student类，我们还定义了映射文件并配置了NHibernate.我们现在可以使用一些查询来执行CRUD操作.
您可以看到我们的Student表中没有数据 NHibernateDemoDB 数据库.
所以要添加一些数据，我们需要执行添加/创建操作，如下所示.
using (var session = sefact.OpenSession()) {
using (var tx = session.BeginTransaction()) {
var student1 = new Student {
ID = 1,
FirstMidName = "Allan",
LastName = "Bommer"
};
var student2 = new Student {
ID = 2,
FirstMidName = "Jerry",
LastName = "Lewis"
};
session.Save(student1);
session.Save(student2);
tx.Commit();
}
Console.ReadLine();
}您可以看到我们创建了两个学生，然后调用 OpenSession 然后调用 BeginTransaction 的Commit().以下是使用NHibernate.Cfg在 Program.cs 文件
using NHibernate.Cfg;
using NHibernate.Dialect;
using NHibernate.Driver;
using System;
using System.Linq;
using System.Reflection;
namespace NHibernateDemoApp {
class Program {
static void Main(string[] args) {
var cfg = new Configuration();
String Data Source = asia13797\\sqlexpress;
String Initial Catalog = NHibernateDemoDB;
String Integrated Security = True;
String Connect Timeout = 15;
String Encrypt = False;
String TrustServerCertificate = False;
String ApplicationIntent = ReadWrite;
String MultiSubnetFailover = False;
cfg.DataBaseIntegration(x = > { x.ConnectionString = "Data Source +
Initial Catalog + Integrated Security + Connect Timeout + Encrypt +
TrustServerCertificate + ApplicationIntent + MultiSubnetFailover";
x.Driver<SqlClientDriver>();
x.Dialect<MsSql2008Dialect>();
});
cfg.AddAssembly(Assembly.GetExecutingAssembly());
var sefact = cfg.BuildSessionFactory();
using (var session = sefact.OpenSession()) {
using (var tx = session.BeginTransaction()) {
var student1 = new Student {
ID = 1,
FirstMidName = "Allan",
LastName = "Bommer"
};
var student2 = new Student {
ID = 2,
FirstMidName = "Jerry",
LastName = "Lewis"
};
session.Save(student1);
session.Save(student2);
tx.Commit();
}
Console.ReadLine();
}
}
}
}现在让我们运行这个应用程序，然后转到SQL Server对象资源管理器并刷新数据库.你会看到上面两个学生现在被添加到NHibernateDemoDB数据库的Student表中.
您可以看到我们的学生表中现在有两条记录.要从表中读取这些记录，我们需要调用OpenSession的 CreateCriteria()，如下面的代码所示.
using (var session = sefact.OpenSession()) {
using (var tx = session.BeginTransaction()) {
var students = session.CreateCriteria<Student>().List<Student>();
foreach (var student in students) {
Console.WriteLine("{0} \t{1} \t{2}",
student.ID,student.FirstMidName, student.LastName);
}
tx.Commit();
}
Console.ReadLine();
}因此，如果您想要记录列表，我们只需简单地说出学生类型列表.
现在通过所有学生使用 foreach ，然后在控制台上打印ID， FirstMidName 和 LastName .现在，让我们再次运行此应用程序，您将在控制台窗口中看到以下输出.
1 Allan Bommer 2 Jerry Lewis
您还可以使用以下代码在OpenSession的 Get()方法中指定ID来检索任何记录.
using (var session = sefact.OpenSession()) {
using (var tx = session.BeginTransaction()) {
var students = session.CreateCriteria<Student>().List<Student>();
foreach (var student in students) {
Console.WriteLine("{0} \t{1} \t{2}", student.ID,
student.FirstMidName, student.LastName);
}
var stdnt = session.Get<Student>(1);
Console.WriteLine("Retrieved by ID");
Console.WriteLine("{0} \t{1} \t{2}", stdnt.ID,
stdnt.FirstMidName, stdnt.LastName);
tx.Commit();
}
Console.ReadLine();
}现在，当您运行应用程序时，您将看到以下输出.
1 Allan Bommer 2 Jerry Lewis Retrieved by ID 1 Allan Bommer
要更新表中的记录，我们需要先获取该特定记录，然后通过调用OpenSession的 Update()方法更新该记录.如下代码所示.
using (var session = sefact.OpenSession()) {
using (var tx = session.BeginTransaction()) {
var students = session.CreateCriteria<Student>().List<Student>();
foreach (var student in students) {
Console.WriteLine("{0} \t{1} \t{2}", student.ID,
student.FirstMidName, student.LastName);
}
var stdnt = session.Get<Student>(1);
Console.WriteLine("Retrieved by ID");
Console.WriteLine("{0} \t{1} \t{2}", stdnt.ID, stdnt.FirstMidName, stdnt.LastName);
Console.WriteLine("Update the last name of ID = {0}", stdnt.ID);
stdnt.LastName = "Donald";
session.Update(stdnt);
Console.WriteLine("\nFetch the complete list again\n");
foreach (var student in students) {
Console.WriteLine("{0} \t{1} \t{2}", student.ID,
student.FirstMidName, student.LastName);
}
tx.Commit();
}
Console.ReadLine();
}现在，当您运行应用程序时，您将看到以下输出.
1 Allan Bommer 2 Jerry Lewis Retrieved by ID 1 Allan Bommer Update the last name of ID = 1 Fetch the complete list again 1 Allan Donald 2 Jerry Lewis
如您所见，ID等于1的LastName从Bommer更新为唐纳德.
要从表中删除任何记录，我们需要首先获取该特定记录，然后通过调用该记录来删除该记录. OpenSession的Delete()方法，如下面的代码所示.
using (var session = sefact.OpenSession()) {
using (var tx = session.BeginTransaction()) {
var students = session.CreateCriteria<Student>().List<Student>();
foreach (var student in students) {
Console.WriteLine("{0} \t{1} \t{2}", student.ID,
student.FirstMidName, student.LastName);
}
var stdnt = session.Get<Student>(1);
Console.WriteLine("Retrieved by ID");
Console.WriteLine("{0} \t{1} \t{2}", stdnt.ID, stdnt.FirstMidName, stdnt.LastName);
Console.WriteLine("Delete the record which has ID = {0}", stdnt.ID);
session.Delete(stdnt);
Console.WriteLine("\nFetch the complete list again\n");
foreach (var student in students) {
Console.WriteLine("{0} \t{1} \t{2}", student.ID, student.FirstMidName,
student.LastName);
}
tx.Commit();
}
Console.ReadLine();
}现在，当您运行应用程序时，您将看到以下输出.
1 Allan Donald 2 Jerry Lewis Retrieved by ID 1 Allan Bommer Delete the record which has ID = 1 Fetch the complete list again 2 Jerry Lewis
您可以看到ID等于1的记录在数据库中不再可用.您还可以在SQL Server对象资源管理器中查看数据库.
